I currently have a small 12x12x18 viv for which im trying to build a background. Since my frog lives in the tank right now, id prefer to build a background without using expanding foam, since id pretty much have to redo the entire tank from scratch, which i would want to avoid right (although id definitely make a new tank with expanding foam!). Anyway, does anyone have any experience making a background out something besides expander foam, like combo of woods rocks and soil? It does not need to cover every last square inch of the background but im looking to make something that does cover a substantial amount of the back, and something that would still allow me to put plants in the background. Anyone have any experience with somrthing like this?